Hepatitis A virus seroepidemiology of elementary school children in New Taipei City in Taiwan

Background To establish the seroepidemiologic data of hepatitis A virus (HAV) vaccine-preventable HAV diseases among school children (7–12 years old) attending elementary schools in New Taipei City, Taiwan. This is a pilot study of an ongoing nationwide study, and will be the reference for a national immunization program. Methods The school children were selected for samplings, based on a multistage stratified sampling method that included 14 variables (4 socioeducational variables, 4 socioeducational variables, and 6 medical facilities' variables). The 29 administrative districts of New Taipei City were categorized into five strata. In total, 936 school children from 14 schools were recruited and bled for the serologic tests of HAV by enzyme-linked immunosorbent assay method. Results The seropositive rate for HAV was 8.33% among the 936 children. From each school, the difference in the seropositive rate for HAV ranged 0–18.75%. There was no significant difference between each stratum (p = 0.059) or grade (p = 0.570); however, there was a difference between schools in the first stratum (p = 0.033) that was associated with different vaccination rates. This study also revealed a significantly greater seropositive rate in the vaccination group (p < 0.001) and in females (p = 0.02). Conclusion The seropositive rate for the HAV was <10% and was mostly associated with the vaccination status. Because of the low HAV vaccination rate and low seropositive rate for the HAV, an effective hepatitis A vaccine is a useful tool to prevent HAV infection. It is worthy to discuss whether to include the HAV vaccine as part of a routine vaccination program in Taiwan.